wow, "masking the real problem" is a choice statement for a dealer to make especially since anyone who spends 5 minutes on this site can see that some 01's have more than their share of SES issues.

Since you authorized the work, it may be hard to get your money back but maybe you can argue that you should only have to pay for the parts and not the labor since they misdiagnosed the problem. I've used that approach with unscrupulous businesspeople before and have had some success with it though I've never had to use it with my Nissan dealer.